Glass mix for opaque containers and method of making the same



h l gatented Fb. .2s,- 193a, I

UNI ED STATES, PATENT( FI -l it oitoWELn; isrivEizLY iririLs, Ma ama v i- GI Ass' Mixroa orAquu coivrninaas ND": METHOD OF MAKING THE SAME,

- No Drawing.- Application filed October 3, 1930'. Serial noQ issese g This invention relates to a glass mix or be strong to resist pressures and handling and batch forv use in making opaque containers. must be heat resisting to Withstand the rapid Black glass has; been made heretofore and changes in temperature and high temperaopaqueglass has also been produced, but a tures employed for sterilization of contents.

' satisfactory glassmix capable of producing t is particularly advantageous to use black 55 glass containers completely impervious to glassfor food containers inasmuch as nu: light rays has not been invented or used heremerous food products are adversely affected tofore. Y The black glass made heretofore by lightrays. 'F or example, fruit juices, contained very large quantities of opacifying suchlaspureorange juice, cannot be stored ingredients and employed pigments or opaciinordinary glass containers for an apprefiers' ofhigh cost. Opaque; glass produced in ciable length oftime, even though saidorange accordance With known methods and for; juicegissaturatedWith carbondioxide under mulas'is, furthermore, very brittle and does pressure, as an enzymatic action or. other ac-' not have thephysic'al durabilitywhich per tion takes place therein by action of-light mits the employment ofsuch glass for the rayspassing' through the container. Con-. 5

manufacture of IGlZLtlVGlYtl'llIl-WfidlGd containers made'from' perfectly opaque glass,

tainers such as bottles, jars, urns, etc. Furhowever, can be used for such food products thermore, ordinary opaque glass is not elas- Without causing such food products tospoil.v

tic t g 51nd is 11017 h t resi ing and The mostccommon method of obtaining a t can not be used in t e ma u Of dark coloration in. glass is to use manganese Ga n rs by h tp n bl w madioxide', but largequantities thereof are nechi 110W customarily usedv for the 11 essary and the glass is not absolutely opaque facture of bottles and the like; but has a purplish tint. Cobalt, copperand An object of-this inventionist pr vi iron oxideshave often been added so as to '25 n disclose a glass miX which Producesv produce aiblack color; All of these opacifya method of making-opaque glass of-such opaque gl ss of h g phy ical du b lity ing agents are expensive and large quantities Another object is to disclose and p vid thereof are necessary'in order to produce an a glass mix rb c c p e e g 1 opaque glass. Even though the glass is in the manufacture of containers imperv ous a u it :i h b t t d b f I 30 to light ys 7 i c 7 suitable for usein the manufacture of glass An object of this invention is to disclose containers, 7 x q 1 a and Provide w and novelglass batch It has been discovered that a black opaque, P y opaclfymg of lowcost' glass suitable for themanufacture of glass Another ob ect 1s to disclose and provide Containers can be made by the hereinafter 85,

described process from any basic formula of the character generally classified as soda lime glass. For example, the basic formula of a soda lime glass which f'may be'vvell used in physical durab-ility as to permit it to'be used in the manufacture of containers.

Ordinary opaque glass -may customarily contain fluorspar, 'bone ash', lepidolite and pyrolusite or manganese dioxide, but the arrylng outthis process may be: 90

glass is extremely brittle and of little n V H strength. For example, the black glass or 74.5 'S1O vitreolite used for purposes ofornamentation' 0,5 A1 0 at the present time is representative of black 17,5 N 0 glass as made heretofore, but such glass is not I 75 r (3 0 9 ada ted for the manufactureofbottlesor- V r 1 a p p v c I oth i' containers because of its susceptibility I W111. 6 u de t d, f Fiourseaithat h to temperature changes and its" brittleness. r l 1 only representatlveof the charace a Glass-containers,particularly when such conter'of the basic; glass from which the opaque s tainers are to be used for food products, must glass may be made. Preferably, however, ,100

the lime content should not exceed about The opacity of the glass is develo ed by adding carbon, metallic oxide capa 1e of forming black sulphide, and sulphur to the glass batch in sufficient quantities to give an opaque glass. It will be found that in this -mannera glass isootained which is completely opaque, has a good gloss, is of high physical durability,'is strong, elastic, tough and heat resisting. V

, The carbon to be used in the mix is preferably in finely divided form and may be graphite, coal, coke, or other similar product. Copper, silver, mercury, nickel, iron, lead and molybdenum produce black sulphides and therefore these metals or their oxides are preferably used. In view of its cost, silver is ordinarily not used. Instead of using a metallic oxide such, for example, as lead oxide, the metal itself in finelydivided form may be used. The sulphur is preferably a technical. grade of sulphur in the crystalline finely divided form. A sulphide or other salt containing sulphur may be used, but the substituting lead oxide for part of the copper, the resistance of the glass to shock, hot water and pressure is increased. By using lead oxide alone, however, glass is rendered too soft and the bottles made therefrom do not set quickly enough, tending to lose their shape while being transferred from the-bottle making machine to the lehr. v

. It is to be understood that the proportions of metallic oxides added to the glass will vary with the character of the batch being treated and the characteristics of the glass tank employed. The availability of opacifiers or other metallic oxides influences the type of metallic oxide employed. For example, a

plant near a copper-molybdenum mine may find it economical to use a sludge residual oxide from the mine operations, which would be perfectly satisfactory to produce the black opaque color. i

In carrying out the invention, the sulphur, carbon and the metal or metallic oxide or oxides are intermixed in proper proportion and.

then added to the rest of the batch material such as sand, lime, alkali, .cullet, etc., and then fed to the glass furnace at regular filling intervals. The sulphur, carbon and metallic glass furnace, as otherwise the carbon added to the mix would be expelled to a large extent in the'form of carbon dioxide, and the sulphur in the form of sulphur dioxide. For this reason it is also desirable to employ the lower oxides of the metals. If oxidizing conditions exist in the glass furnace, the black metallic sulphide which it is desired to form would be formed only partially, with the possibility of its being oxidized to colorless or colored salts of no value as opacifying elements. The black metallic oxides which form the opacifying ingredient of the finalglass are formed, therefore, by-the reducing action of the carbon and sulphur upon the metal or metallic oxide, and in view of the fact that such metallic sulphide is formed in the glass itself during melting, their efficiency is greatly increased.

Although sulphur, carbon and metallic ox ides have been individually employed in glass batches, there is no similarity whatsoever between the results obtained by such individual use of the ingredients and the results obtained when these materials are used'in combination in accordance with this invention.

As an illustrative example of a glass mix capable of producing a dense, opaque, black, glossy glass adapted for use in the manufacture of durable, heat resisting bottles or containers', the following composition is given;

Per cent 2100 lbs. sand 50 1000 lbs. cullet 23 800 lbs. soda ash l 18.3 360 lbs. limestone 8.05 18 lbs. sea coal 04:1 8 lbs. sulphur 0.185 1.75 lbs. copper oxide 0.035 1 lb. lead oxide 0.02

It is to be understood that the above specific example is merely illustrative, and the invention is not limited to the specific proportions there defined. Preferably, the total quantity of carbon, sulphur and metal or metallic oxides added to a basic glass formula should not exceed 2% thereof. Normally, from about 0.6 to about 0.2% of these ingredients may be added to a basic glass formula of the character described hereinabove, and result in the production of a black, perfectly opaque glass of the desired physical durability for use in the manufacture of glass con tainers, either by the blower blow and press machines or by means of other glass forming machlnes or methods.

In making up a composition such as is specifically defined hereinabove, the metallic oxides may be mixed with a little wetsand, sea

coal and sulphur. in a smallcontainer, such as a bucket, and then added to the weighted car of sand as it is dumped into the mixing hopper. Soda, lime-and cullet arethendumped into the mixer in proper quantities, and the 1 whole batch thoroughly mixed and then .carried onto the automatic conveyors to the batch storage bins, from which the complete mixture is sent to the glass tanks. q r

I claim:

'1. In a process of making black glass which will not transmit light into containers made therefrom, the step of adding an opacifier containing carbon, sulfur and copper and lead in a low state of oxidation to a glass mix capable of forming a black sulphide, and sulphur, the carbon,,metallic oxide .and sulphur being present in suflicient quantity to producea black, opaque glass.

3. A glass mix or batchcontaining carbon,

lead monoxide and sulphur in suflicient quan--v tity to produce an opaqe, black glass.

4. A soda lime glass mix or batchcontaining a mixture of carbon, sulphur and a metallic oxide capable of formin'g a black suphide, in quantities sulficient to form an'opaque glass suitable for use in containers.

5. A glass mix or batch containing lead monoxide, cuprous oxide, carbon and sulphur in quantity notexceeding about 2% of the glass mix, but suflicient'to formanopaque glass suitable for use in containers. f

6. A black, opaque glass whichwill not transmit light into containers made thererom said lass bein obtained b addin a a l b g y b tainers formed thereof. 1

mixture of carbon, sulfur and cuprous and lead oxides-to a soda lime glass'batch, said carbon, sulfur and cuprous and lead oxides being capable of forming blaoksulfideduring opacifier being present in quantity not ex 'ceeding about 2% of the glass mix but sufiicient to product an'opaque glass which will not transmit light into containersmade therefrom. I

8- A- glass mix added opacifier comprising copper and lead oxides, carbon and sulfur, said opacifier being added in quantity notexceeding about 2% of the glass mix but sufiicient to produce an opaque glass which will not transmit light into containers made'therefrom;

or batch containing j an '9. A glass mix or batch containing a metal lic oxide capable of forming a blacksulfide, carbon and sulfur in quantity not exceeding about 2% of the glass mix but sufiicient to produce an opaque glass which will not transmit light into containers made therefrom.

I 10.A glass mix or batch containing car; bon, a metallic oxide capable of forming a black sulfide and sulfur in sufficient quantities A togive'an opaque glasswhich will not trans-" mit light into containers made therefrom.

11; Aglass mix or batch containing the in following 'materi'als in approximately the proportions stated Percent.

74;.5 '..SiO

0.5 A12O3 17.5 NaO 7.5-. CaO

, towhic'h is added a mixture of carbon, sul-.

fur and metallic oxides capable of forming a black sulfide in quantities suflicient to form an opaque glass suitable for use in contains ers which will not transmit light.

12. A glass mix or batch containing carbon, sulfur and a metallic oxide capable of form- I 13. A glass mix or batch containing carbon, sulfur and a metallic oxide capable offorming a black sulfide during the melting operation, said metallic oxide, carbon and sulfur to produce a glass which is black and opaque and which will not transmit light into con- 14. A glass opacifier capableof producing anopaque black glass which will nottran'smit light into containers made therefrom, said opacifier containing carbon, sulfur and metallic oxide capable of forming black sulfide, carbon being the main ingredient ofsaid opacifier. A

15. A glass opacifier capable of producing van opaque black glasswhich will not transmit light into containers 'made therefrom,,said

opacifier containing carbon, sulfurand cop per and lead in a low, state of oxidation. 1

Signed at Los Angeles, California, this 5th day of June, 1930. V i 3 CLARENCE W. CR-OWELL.

ing a black sulfide during the melting operation,said metallic oxide,'carbonand sulfur constituting between 1% and 2% of the glass mix andadapted to produce a glass which is opaque and which will not transmit lightinto containers formed thereof. 

